Sullivan, TD 2020, 'Hydromechanical coupling concepts for mine slopes', in PM Dight (ed.), Slope Stability 2020: Proceedings of the 2020 International Symposium on Slope Stability in Open Pit Mining and Civil Engineering
, Australian Centre for Geomechanics, Perth, pp. 65-98, https://doi.org/10.36487/ACG_repo/2025_0.04
In soil and rock environments, effective management of any excavation is dependent on an understanding of the slope movements and the factors that influence these. Slope movements cover a continuum from small deformations to collapse. These movements are nearly always of sufficient magnitude to affect the physical properties of the rock mass, the groundwater contained therein and the potential impacts from external loading events. Consequently, a thorough understanding of the mechanisms and the roles of stress, creep movements, instability, ground and surface water impacts at each stage of the movement process is fundamental for effective management and control of slopes.
This paper covers the theory and practice with excavated slopes in lower strength materials in some typical geotechnical settings focussed on the roles of ground movements, ground and surface water interaction and hydromechanical coupling. Wide experience has demonstrated there are common behavioural patterns associated with these typical geotechnical settings. The behavioural patterns comprise the processes, interactions and responses; which occur to various degrees throughout most stages of the life of an
The paper deals with soil and soft rock, footwalls and inclined layered or bedded sequences. However, the same concepts and ideas also apply to various extents to jointed hard rock and complex geological/geotechnical materials. The examples are based on large-scale monitored performance. The paper shows how the geotechnical and hydrogeological character of the materials leads to complex interactions between the various factors. The aim of the paper is to provide practical guidance for professionals working in the mine slope environment.
Keywords: hydromechanical coupling, mine slopes, pit slope movement, in situ stress, groundwater, transient groundwater pressures, geotechnical settings
Alonso, EE, Gens, A & Delahaye, CH 2003, ‘Influence of rainfall on deformation and stability of a slope in overconsolidated clay’, Hydrogeology Journal, no.11, pp. 174–192.
Beale, G & Read, JR 2013, ‘Guidelines for evaluating water in pit slope stability’, CSIRO Publishing, Clayton.
Burland, JB, Longworth, TI & Moore, JFA 1977, ‘A study of ground movement and progressive failure caused by a deep excavation in Oxford Clay’, Geotechnique, vol. 27, issue 4, pp. 557–591.
Burman, BC & Sullivan, TD 1985, ‘Dewatering and depressurisation studies for development of the Lochiel open pit mine South Australia’, Proceedings of 2nd International Mine Water Congress, Asociacion Nacional de Ingenieros de Minas and International Mine Water Association, Granada, pp. 307–324,
Carlsson, A & Olsson, T 1979, ‘Hydraulic conductivity and its stress dependency’, Proceedings of the Workshop on Low-flow,
Low-permeability Measurements in Largely Impermeable Rocks, Organisation for Economic Cooperation and Development and the Nuclear Energy Agency,, Paris, pp. 249–260.
Esaki, T, Du, S, Mitani, Y, Ikusada, K & Jing, L 1999, ‘Development of shear-flow test apparatus and determination of coupled properties for a single rock joint’, International Journal of Rock Mechanics Mining Science, vol. 36, pp. 641–650.
Hoek, E & Brown, ET 2018, ‘The Hoek-Brown failure criterion and GSI – 2018 edition’, Journal of Rock Mechanics and Geotechnical Engineering, vol. 11, issue 3, pp. 445–463.
Johnston, I 1991, ‘Geomechanics and the emergence of soft rock technology’, Australian Geomechanics Journal, vol. 21, pp. 3–26.
Londe, P 1987, ‘The Malpasset Dam failure’, Engineering Geology, vol. 24, pp. 295–329.
Louis, C & Maini, Y 1970, ‘Determination of in-situ hydraulic parameters in jointed rock’, Proceedings of the International Congress of Rock Mechanics, vol. 1, International Society of Rock Mechanics, Salzburg, pp. 235–245.
Makurat, A, Barton, N & Rad, NS 1990, ‘Joint conductivity variation due to normal and shear deformation’, Rock Joints, Balkema, Rotterdam, pp. 535–540.
National Research Council 1996, Rock Fracture and Fluid Flow, National Academy Press, Washington DC.
Neuzil, CE 2003, ‘Hydromechanical coupling in geologic processes’, Hydrogeology Journal, vol. 11, pp. 41–83.
Neuzil, CE & Tracey, JV 1981,’ Flow through fractures’, Water Resources Research, vol. 17, pp. 191–199.
O'Brien, MD & Sullivan, TD 1988, ‘The Lochiel Trial Pit - design and excavation’, Proceedings of the Conference Minerals and Exploration at the Crossroads, Australasian Institute of Mining and Metallurgy, Parkville, pp. 127–133.
Olsson, R 1992, ‘Site characterisation and validation - final report: Strippa Project’, Swedish Nuclear Fuel Waste Management Co, Stockholm.
Olsson, R & Barton, N 2001, ‘An improved model for hydromechanical coupling during shearing of rock joints’, International Journal of Rock Mechanics Mining Science, vol. 38, pp. 317–329.
Rutqvist, J & Stephansson, O 2003, ‘The role of hydromechanical coupling in fractured rock engineering’, Hydrogeology Journal, vol. 11, pp. 7–40.
Rutqvist, J, Tsang, CF, Ekman, D & Stephannson, O 1997, ‘Evaluation of in situ hydromechanical properties of rock fractures at Laxemar in Sweden’, Proceedings of the 1st Asian Rock Mechanics Symposium, International Society for Rock Mechanics, Lisbon,
Snow, DT 1968, ‘Rock fracture spacing, openings and porosities’, Journal Soil Mechanics Division, vol. 94, issue 1, pp. 73–91.
Sullivan, TD 1994, ‘Mine slope design - The chances of getting the answer right and the risk of getting it wrong’, Proceedings of the Fourth Large Open Pit Mining Conference, Australasian Institute of Mining and Metallurgy, Parkville.
Sullivan, TD 2008, Yallourn Mine Batter Failure Inquiry, Victorian Government Printer, Melbourne.
Sullivan, TD 2007, ‘Hydromechanical coupling and pit slope movements’, Proceedings of the 2007 International Symposium on Rock Slope Stability in Open Pit Mining and Civil Engineering, Australian Centre for Geomechanics, Perth, pp. 3–43,
Sullivan, TD 2010, ‘The geological model’, in AL Williams, GM Pinches, CY Chin, TJ McMorran & CI Massey (eds), Proceedings of the 11th Congress of International Association for Engineering Geology and the Environment, CRC Press, Boca Raton,
Sullivan, TD & Burman, BC 1985, ‘Geological and geotechnical aspects of small basins and their effects on mining’, Proceedings of the Asian Mining Conference, Institute of Mining and Metallurgy, London, pp. 321–335.
Sullivan, TD & Burman, BC 1986, ‘The Lochiel Project - a case study of geotechnical engineering studies in a difficult environment’, in JT Woodcock (ed.), Proceedings of the 13th Council of Mining and Metallurgical Institutions Congress, Australasian Institute of Mining and Metallurgy, Parkville, pp. 1–10.
Witherspoon, PA, Wang, JSY, Iwai, K & Gale, JE 1980, ‘Validity of the cubic law for fluid flow in deformable rock fracture’, Water Resources Research, vol. 16, pp. 1016–1024.
Wladis, D, Jonsson, P & Wallroth, T 1997, ‘Regional characterisation of hydraulic properties of rock using well test data’, Technical report, Swedish Nuclear Fuel Waste Management Co, Stockholm.
Wyllie, DC & Mah, CW 2004, ‘Rock Slope Engineering - Civil and Mining’, 4th edn, Spon Press, London.